STUD 2030250 - Caterpillar

Piston Pin Bearings
Note: This procedure requires personnel with the correct training and the use of specialized equipment for machining.If the piston pin bearing requires replacement but the original connecting rod is not replaced, the following procedures must be performed:
Determine the grade of length of the connecting rod. Use one of the following characteristics:
The mark
The color
Measuring the lengthNote: The length of the connecting rod is measured when the following items are completed: Remove the bearing for the crankshaft journal. and Install the original piston pin bearing in the connecting rod. Refer to "Measure The Length Of The Connecting Rod" in this service module.
Ensure that the connecting rod is aligned parallel and that the connecting rod is not distorted. Refer to "Distortion of The Connecting Rod" in this service module.
Remove the piston pin bearing from the connecting rod. Install a new bearing in the connecting rod. The new bearing is partially finished. The new bearing must be bored off-center to the correct diameter. This off-center position is determined by the grade of length of the connecting rod. Refer to Table 1. The correct diameter of the bore in the piston pin bearing is given in the Specifications Module, "Connecting Rod". Surface finish of the bored hole in the piston pin bearing ... Ra 0.8 micrometers
Machine the ends of the piston pin to the correct length. Remove any sharp edges. Refer to the Specifications Module, "Connecting Rod".
If the grade of length of the connecting rod is changed, the letter that is stamped on the connecting rod must be removed. Etch a letter that is for the new grade of length on the side of the connecting rod. Note: Do not stamp a new letter on the connecting rod. The force of stamping may damage the connecting rod.Table 1 references the following information: grade of length of the connecting rod and lengths of the connecting rods
Table 1
Grade Letter Color Code Length Of The Connecting Rod (CRL)
"F" Red 165.728 to 165.761 mm (6.5247 to 6.5265 inch)
"G" Orange 165.682 to 165.715 mm (6.5229 to 6.5247 inch)
"H" White 165.637 to 165.670 mm (6.5211 to 6.5229 inch)
"J" Green 165.591 to 165.624 mm (6.5193 to 6.5211 inch)
"K" Purple 165.545 to 165.578 mm (6.5175 to 6.5193 inch)
"L" Blue 165.499 to 165.532 mm (6.5157 to 6.5175 inch)
S(1) - 165.571 to 165.635 mm (6.5185 to 6.5210 inch)
(1) A new piston and a new piston pin bearing have been installed.Measure The Length Of The Connecting Rod
If the mark or the color of the grade of length cannot be observed on the connecting rod, perform the following procedure:
Illustration 1 g00326546
Measure the length of the connecting rod.
(1) Measuring pins
(2) Connecting rod
(CRL) Connecting Rod Length
Refer to Illustration 1. Use the following tools in order to measure the length of the connecting rod:
Appropriate gauges for measuring distance
Measuring pins (1)
Be sure that the measuring pins (1) are parallel. "CRL" is measured when the bearing for the crankshaft journal is removed and the original piston pin bearing is installed. Measure "CRL". Compare